It is known in the art to fracture rocks by passing pulses of current between electrodes within a formation. Melton and Cross in Quarterly, Colorado School of Mine, July 1967, Vol. 62, No. 3, pp. 25-60, disclosed field tests in which alternating current electricity was passed through oil shale to create horizontal permeable paths for subsequent fire flooding to heat the oil shale and produce hydrocarbons by thermal cracking of kerogen.
In U.S. Pat. No. 7,631,691, methods are disclosed to fracture a formation by first providing wells in a formation, and then one or more fractures are established in the formation such that each fracture intersects at least one of the wells. Electrically conductive material is subsequently placed in the fracture, and an electric voltage is applied across the fracture and through the material to generate heat to pyrolyze organic matter in the formation to form producible hydrocarbons.
U.S. Pat. No. 7,270,195 discloses methods and apparatuses to form a bore during drilling operations by plasma channel drilling using high voltage, high energy, and rapid rise time electric pulses. US Patent Publication No. 2013/0255936 discloses a method to produce hydrocarbons from a formation by applying differential voltage between a pair of electrodes placed within a formation to remove a fraction between 10−6 and 10−4 of the mineral mass in the formation between the electrodes, followed by the production of hydrocarbons, e.g., natural gas, from the formation.
There is still a need for improved systems and methods for fracturing of formations, particularly controlled fracturing in large volumes of tight geologic formations to create multi-dimensional patterns of fracture within, for the economic recovery of any of solids, liquids and gases.